GaAsN material systems have become important due to its bandgap that enables long wavelength (1.3 to 1.6 micrometer) light sources to be made on GaAs substrates. This capability has for example, led to the development of a new generation of long wavelength VCSELs utilizing GaAs-based distributed Bragg reflecting mirrors. The large bandgap offsets in InGaAsN material systems result in high laser characteristic temperatures TO. The reduced temperature sensitivity makes InGaAsN attractive for high power lasers.
However, one problem with such high powered lasers is the facets of the laser absorbs energy from the laser. The absorbed energy heats the facet causing defects and bandgap shrinkage. The resulting defects and bandgap shrinkage increases facet energy absorption in cycle that sometimes results in catastrophic optical damage at the laser facet and laser failure.
Thus an improved system to minimize facet heating is needed.